Question

Falling rate period of drying process is one during which:
A. Drying rate depends mainly on properties of food material
B. Moisture is not available on the surface of food material
C. Drying rate decreases
D. Drying rate depends only on the capacity of drying air to pickup moisture from the surface
E. Drying rate remains constant
Choose the correct answer from the options given below:

• A. C, D Only
• B. A, C Only
• C. B, E Only
• D. B, C Only

Hint:

Falling rate period: moisture movement is diffusion-controlled.
Drying rate decreases and depends on material properties.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Drying process has different periods: constant rate period and falling rate period.
In the falling rate period, the drying rate decreases.

Step 2: Key Formula or Approach:
No specific formula.
Need to understand the characteristics of the falling rate period.

Step 3: Detailed Explanation:
In the falling rate period, moisture is not available on the surface.
The drying rate decreases as moisture moves from inside to the surface.
The drying rate depends on the properties of the food material.
It does not depend on the drying air capacity (that is for constant rate period).
Thus, B and C are correct.

Step 4: Final Answer:
The correct statements are B and C.
Hence, the correct option is (D).